This patch reads program arguments from the config file and makes them
available to the application via the 'argc' and 'argv' arguments of the
'main()' function. The configuration syntax looks like this:
<config>
<arg value="...">
<arg value="...">
...
</config>
The 'value' attribute of the first <arg> node becomes 'argv[0]' and so on.
Fixes#184.
Christian Prochaska